Four Seasons helps General Mills improve production, reduce waste and save 70% in energy costs.   Enjoying your favourite breakfast cereal is easy; add some milk, scoop it into your mouth and crunch away. Making breakfast cereal is a far more technically challenging process, requiring specially-designed equipment that mixes just the right amount of ingredients, and prepares the cereal in just the right way to achieve the desired size, shape, colour, texture and taste.   General Mills, maker of such cereals as Cheerios, Wheaties and Golden Grahams was facing two big challenges with production at their Toronto plant. The first challenge was to reduce the amount of reject product coming off the processing line. The second challenge was to increase production to meet growing demand. Solutions to both challenges depended on improving the cereal drying/cooling process. This is the part of the process where the hot, steamy, freshly-made cereal is prepared for packaging.   The cereal at the General Mills plant in question was dried in a large oven operating at 260 degrees. After passing through the oven, cool air brought in from the outside was blown over the cereal to cool it off and to remove any excess moisture. Because untreated, outdoor air was used, line operators had to constantly compensate for variations in temperature and humidity. The result was often wasted product and costly production delays. To compensate for the inefficiencies General Mills wanted to install a second drying/cooling line, but the cost of a second line was prohibitive.   General Mills called on Four Seasons Controlled Climates to develop an alternate solution. After carefully studying the situation, Four Seasons developed the proverbial "one-stone solution" by designing and installing an upgrade to the existing system which solved both the quality control problem and the production capacity issue. Four Seasons' solution involved taking outside air and dehumidifying it to remove excess moisture. Then, hot, exhaust air from another part of the cereal-making process was used to preheat the dehumidified outdoor air, which was then routed to the drying oven and heated further to the necessary temperature. By preheating the outdoor air and removing the humidity, the oven which previously operated at 260 degrees, now needed to operate at only 185 degrees to achieve the same air temperature and humidity level.   With the new system in place, the entire process was now much more controlled and predictable. Waste from the drying/cooling process was reduced to virtually nothing, while the capacity of the line increased 180%, from 110 lbs. of cereal per minute to 200 lbs. per minute. Besides the improvements in production, there was a tremendous energy savings as well. Overall, the improved system saved 70% of the energy that would have been consumed had General Mills installed a second drying/cooling line in order to increase production.   Reduced waste, increased production and lower energy costs. Needless to say, General Mills was impressed. And so was the government of Canada. In recognition of the energy savings achieved by the improvements, General Mills was awarded a government grant to help pay for the system designed and installed by Four Seasons.   Cheerio!       back to PilotLight online